1. Field of the Invention
The present invention generally relates to a data accessing system, a controller and a storage device having the same, and an operation method thereof, in particular, to a data accessing system for interfacing between a non-volatile memory and a smart card, a controller and a storage device having the same, and an operation method thereof.
2. Description of Related Art
A memory card is a data storage device which usually uses a NAND flash memory as its storage media. A NAND flash memory is writable and erasable, and which offers power-free storage. Besides, a NAND flash memory is a non-volatile memory therefore it has the advantages of non-volatile memory such as small volume, fast access speed, and low power consumption. In addition, a NAND flash memory has high operation rate because easing data stored therein is made in a unit of block. Memory cards have been broadly applied to personal data storage due to its small volume, large capacity, and high portability. However, the data stored in a memory card may be stolen when the memory card is lost.
A smart card is an integrated circuit (IC) chip having a microprocessor, a card operating system, a security module, and a memory for executing certain operations. A smart card can provide such functions as calculation, encryption, bi-directional communication, and security such that the smart card not only stores data but also protects the data stored therein. One of the applications of smart card is the subscriber identification module (SIM) card used in a GSM (Global System for Mobile Communications) cellular phone.
To protect the data stored in a memory card, a NAND flash memory integrated with the security mechanism of a smart card is provided. However, the data used by applications in a smart card is usually composed of small data, for example, lower than 256 bytes. Thus, the life of a NAND flash memory will be shortened if the NAND flash memory is erased every time the data stored therein is slightly updated.
Accordingly, a data accessing mechanism between a NAND flash memory and a smart card is to be developed.